1. Field of the Invention
This invention relates to a control system for cameras connected to a network.
2. Description of the Related Art
There is a known camera control system capable of operating one monitoring camera or a plurality of monitoring cameras by remote control from a distant place. Such monitoring cameras vary from a type in which a camera is fixed on a table so as to be always directed in one direction to a type in which a camera can pan, tilt, and zoom by external control. The latter commonly includes the function of changing both the direction of photographing and magnification by remote control from a monitoring center.
When a plurality of cameras are operated by remote control, where and in which direction the respective cameras are installed need to be indicated to the operator. For example, for a monitoring system in which many cameras are installed in a store, a factory or a building, a camera information display system has been proposed. In such a camera information display system, figures representing the cameras are displayed at the appropriate positions in accordance with the respective cameras so that the figures overlap with an installation position map.
According to the camera information display system, the user as an observer can visually understand the location of the camera being operated. However, the above system hardly provides the user with sufficient displayed camera information.
For example, although the user can recognize the location(s) of the camera(s) being controlled on the map, the user cannot easily understand from which camera one image on the display screen is sent or from which cameras a plurality of images on the display screen are sent, based on the displayed information on the map.
In addition, in the above system the user cannot easily recognize on the map whether or not the camera(s) can be externally controlled with respect to photographing conditions such as panning, tilting and zooming.
Further, conventionally, one communication terminal is connected to at least one camera, and an image taken by a selected camera is transmitted, or images (or a composite image) taken by selected cameras are transmitted, to the monitoring controller of a monitoring center through a computer network. The above system has no means for using the map to recognize whether the cameras are connected to the same communication terminal. For example, in connection with switching over cameras connected to the same communication terminal, if the user can utilize a video display window that is assigned to the communication terminal without changing the window, troublesome or time-consuming operations (such as switching over the video display window to another window or creating a new window) can be eliminated because the user immediately understands whether or not a desired image can be obtained from a different camera connected to the same communication terminal. Accordingly, the user would experience improved operability.